Given

f

:

$\{$

$0$

$,$

$1$

$\}$

$4$

$->$

$\{$

$0$

$,$

$1$

$\}$

$3$

f:$\{0,1\}$

$4$

$->\{0,1\}$

$3$

where

f

$($

x

$)$

f$($x$)$ is obtained by removing the first bit from

x

x$.$ For example,

f

$($

$1000$

$)$

$=$

$000$

f$(1000)=000.$ Select the correct description of the function

f

f